In the course of our recent investigations of the cholinergic effects of drugs on skeletal neuromyal transmission we investigated the related effects of catechol and xanthine derivatives and described the action of certain xanthines on the intercostal nerve muscle preparations which we obtained from myasthenia gravis patients; their effectiveness in biopsies obtained from refractory to antiChE therapy led us to a clinical trial of a zanthine, oxtriphylline. As the clinical results were favorable and as there was an indication of favorable interactions of oxtriphylline with anticholinesterase and corticotropin therapy, the present application is directed at expansion and further analysis of these findings. The proposed investigations require and are based on, the proven collaboration of the staff of the Department of Pharmacology and Clinical Neurology.